Catheter

Abstract

The purpose of the present invention is to provide a catheter that makes it possible to appropriately fix a sensor without bonding.　Provided is a catheter (100) in which is incorporated a sensor (30) that has a sensor body (31) provided at one end of a transmission cable (32), said catheter (100) comprising a tube (12) in which is formed a lumen (15) that is in communication with an opening (16, 17) formed at a tip end, and which has a pair of holding parts (2, 23) that hold the sensor (30) by sandwiching the sensor (30) in a direction along the inner periphery of the lumen (16, 17).

Description

catheter

[0001] The present invention relates to a catheter incorporating a sensor having a sensor body provided at one end of a transmission cable.

[0002] Acute kidney injury (AKI), which occurs in 30% to 50% of patients hospitalized in intensive care units, adversely affects patient prognosis even in mild cases, and the mortality rate for patients requiring blood purification is as high as 60%. Progression to chronic renal failure is also a problem. One of the causes of AKI is hypoxia in the renal medulla, and it is believed that renal medullary oxygen partial pressure can be estimated by measuring the urinary oxygen partial pressure in the bladder. To measure the oxygen partial pressure in urine in the bladder, a catheter has been proposed that measures the oxygen partial pressure in the bladder or bladder wall by protruding an oxygen partial pressure measurement sensor from a side hole of a urethral catheter (see, for example, Patent Document 1). Another proposed catheter has an oxygen partial pressure measurement sensor with a sensor body attached to one end of a transmission cable inserted into the urination lumen of the catheter from the proximal end, with the sensor body positioned in the urination lumen at the distal end of the catheter.

[0003] JP 9-505505

[0004] However, in the above-mentioned prior art catheters in which the oxygen partial pressure measuring sensor is disposed within the urination lumen of the catheter, the sensor body is fixed by adhesive to the inner circumferential surface of the tube at the tip of the catheter.

[0005] If the purpose is to measure urinary oxygen partial pressure during surgery, the catheter body can be left in the body and continued to be used after the surgery is completed, but the oxygen partial pressure measurement sensor inserted into the catheter body becomes unnecessary after the surgery.

[0006] Furthermore, if the transmission cable extends from the base end of the catheter to the outside, it may get caught on an external object or person, and in the case of a balloon catheter in particular, there is a risk that the catheter may be forcibly pulled out along with the transmission cable while the balloon is still inflated.

[0007] Furthermore, it is difficult to remove the transmission cable from the proximal end of the catheter while leaving the catheter inside the body and peeling off the oxygen partial pressure measuring sensor adhered to the distal end of the catheter.

[0008] SUMMARY OF THE INVENTION An object of the present invention is to provide a catheter that can solve the problems of the conventional techniques described above and can properly fix a sensor without adhesive.

[0009] The present invention is characterized in that a catheter incorporating a sensor having a sensor body attached to one end of a transmission cable is provided with a tube having an inner lumen communicating with an opening formed at the tip, the tube having a pair of holding portions that sandwich and hold the sensor in a direction along the inner circumference of the lumen.

[0010] In this case, the device may further include a guide portion that guides the sensor in a direction away from the inner circumferential surface of the lumen. The guide portion may have a wedge-shaped abutting end that abuts against the sensor. The guide portion may be attached to the holding portion. The guide portion may be defined by the holding portion along the tube and formed to block the cable holding lumen near the tip. The device may further include a balloon provided on the outer periphery of the tube, and the abutting end of the guide portion that abuts against the sensor may be located inside the balloon. The device may further include a balloon provided on the outer periphery of the tube, and the holding portion may be located inside the balloon. The tube may contract when the balloon expands, thereby narrowing the gap between one holding portion and the other holding portion.

[0011] The present invention can provide a catheter that can properly fix a sensor without adhesive.

[0012] Fig. 1 shows a side view of a balloon catheter according to this embodiment; Fig. 2 shows a transverse cross-sectional view of the balloon catheter with the balloon inflated; Fig. 3 shows a transverse cross-sectional view of the proximal end of the balloon catheter; Fig. 4 shows a longitudinal cross-sectional view of a tube; and Fig. 5 shows a perspective view of a guide portion.

[0013] Preferred embodiments of the present invention will now be described with reference to the drawings: Fig. 1 shows a side view of a balloon catheter, Fig. 2 shows a cross-sectional view of the balloon catheter with the balloon inflated, Fig. 3 shows a cross-sectional view of the proximal end of the balloon catheter, Fig. 4 shows a longitudinal cross-sectional view of the tube, and Fig. 5 shows a perspective view of the guide portion.

[0014] 1, the balloon catheter 100 includes a catheter body 10, a sensor 30, and a fixing part 40. The balloon catheter 100 is an integrated product in which the fixing part 40 is attached to the catheter body 10 and the sensor 30 is fixed to the catheter body 10 via the fixing part 40.

[0015] The catheter body 10 is composed of a tip portion 11, a tube 12, a balloon 13, and a branch portion 14, and the tip portion 11 and the balloon 13 are connected to the tube 12 at the tip side of the catheter body 10, while the branch portion 14 is connected to the tube 12 at the base end side of the catheter body 10 to form an integrated unit.

[0016] The tip portion 11, the tube 12, the balloon 13, and the branch portion 14 are formed of silicone rubber, but may also be formed of latex, natural rubber, isoprene rubber, thermoplastic resin such as PVC and urethane rubber, fluororubber and fluororesin, etc.

[0017] As shown in Figure 2, the tube 12 penetrates the balloon 13, and the balloon 13 is attached to the outer periphery near the tip by adhesive. That is, the balloon 13 is formed to surround the entire circumference of the tube 12. The tube 12 also has a cylindrical tip portion 11 attached to the end face of the tip by adhesive. The tube 12 has a urination lumen 15 (inner cavity) 15 for allowing urine to flow, formed along the extension direction of the tube 12. The urination lumen 15 communicates with the outside via a tip hole (opening) 16 and a side hole (opening) 17 formed in the tip portion 11. Urine flowing in through the tip hole 16 and the side hole 17 passes through the urination lumen 15 and flows to the branch portion 14 on the base end side.

[0018] A portion of the tube 12 is thick-walled, and a balloon lumen 18 for inflating the balloon 13 is formed in this thick-walled portion along the extension direction of the tube 12. The balloon lumen 18 is fluidly connected to the inside of the balloon 13 near the tip, and the balloon 13 is inflated by filling it with sterilized water supplied from the branch portion 14 on the base end side.

[0019] The urination lumen 15 is formed to have a substantially circular flow passage cross section, and the balloon lumen 18 is formed to have a smaller circular flow passage cross section than the urination lumen 15 .

[0020] The balloon 13 is formed to have a cylindrical shape when not inflated. The non-inflatable portions of the balloon 13 on the distal and proximal ends are tapered so that the outer diameter gradually decreases toward the distal and proximal ends. When sterile water is supplied from the branching portion 14 via the balloon lumen 18, the balloon 13 expands into a spherical shape centered on the tube 12 between the distal inflation end 13A and the proximal inflation end 13B. This allows the balloon catheter 100 to be fixed in the patient's bladder by the balloon 13 being caught and prevented from slipping out.

[0021] As shown in FIG. 3, the branch portion 14 is connected to the tube 12 at its distal end, and is divided into three portions at its proximal end: a balloon injection port 19, a transmission cable insertion port 20, and a urination port 21.

[0022] The balloon inlet 19 is fluidly connected to the balloon lumen 18 and can be connected to a reservoir (not shown) for injecting sterile water into the balloon lumen 18 .

[0023] The transmission cable insertion port 20 extends linearly relative to the urination lumen 15, and the sensor 30 inserted straight into the transmission cable insertion port 20 is inserted straight into the urination lumen as is.

[0024] The urination outlet 21 extends obliquely relative to the urination lumen 15, and is connectable to a urination tube (not shown) or the like, and is connected to a urine bag or the like via the urination tube.

[0025] As shown in Figure 2, the sensor 30 inserted into the transmission cable insertion port 20 comprises a sensor body 31 and a transmission cable 32. The sensor 30 according to this embodiment is an oxygen partial pressure measurement sensor, in which the sensor body 31 is an excitation light emitting section, and the transmission cable 32 is an optical fiber, which is made of a material that is harder and more elastic than the tube 12. A fluorescent material is applied to the inside of the urination lumen 15 of the tube 12, and light transmitted from the transmission cable 32 is irradiated onto the fluorescent material from the sensor body 31.

[0026] As shown in FIG. 3, the fixing portion 40 is attached to the transmission cable insertion port 20, and the sensor 30 is fixed to the tube 12 via the fixing portion 40 that fixes the transmission cable 32.

[0027] The fixing part 40 includes a fixing part main body 41, a fixing part cap 42, and a fastening part 43. The fastening part 43 has an annular shape with a through hole 43A formed in the center, through which the transmission cable 32 can pass. In the fixing part 40, the fastening part 43 is sandwiched between the fixing part main body 41 and the fixing part cap 42, which is screwed onto the fixing part main body 41. When the fixing part cap 42 is screwed onto the fixing part main body 41, the fastening part 43 is crushed, reducing the diameter of the through hole 43A. As a result, the fastening part 43 fastens the transmission cable 32, thereby fixing the transmission cable 32.

[0028] 4, the tube 12 according to this embodiment has a pair of cable holders 22, 23 formed inside the urination lumen 15 for holding the transmission cable 32. The cable holders 22, 23 are formed integrally with the tube 12 in a plate shape and extend along the urination lumen 15 from the distal end to the proximal end of the tube 12.

[0029] The urination lumen 15 is defined by the cable holding portions 22, 23 into a first area A1 with a large flow area and a second area A2 with a small flow area, and the transmission cable 32 is accommodated and held within the second area A2, which is the cable holding lumen.

[0030] The pair of cable holding portions 22, 23 protrude from the inner peripheral surface of the tube 12 so as to face each other. One cable holding portion 22 and the other cable holding portion 23 protrude from the inner peripheral surface of the tube 12 by the same distance.

[0031] The distance between the cable holding portion tip 22A of one cable holding portion 22 and the cable holding portion tip 23A of the other cable holding portion 23 is smaller than the diameter of the transmission cable 32. This prevents the transmission cable 32 from freely moving to the opposite side of the pair of cable holding portions 22, 23. The pair of cable holding portions 22, 23 are integrally formed from the same soft material as the tube 12.

[0032] A guide portion 24 is incorporated into the second region A2 of the tube 12. As shown in FIG. 5 , this guide portion 24 is formed to have a semicircular cross section and extends like a column, with an arcuate surface 24A and a flat surface 24B. One end of the guide portion 24 is formed with an abutment end 24C that abuts against the sensor 30. This abutment end 24C is formed in a wedge shape and has a slope, and the guide portion 24 guides the sensor 30 by abutting against the transmission cable 32 with the slope of the abutment end 24C.

[0033] The guide portion 24 is incorporated into the second region A2 of the tube 12, with the arcuate surface 24A coming into close contact with the inner circumferential surface of the tube 12 and the flat surface 24B coming into close contact with the cable holding portions 22, 23. In this way, the guide portion 24 closes the second region A2, which is the cable holding lumen, near the tip of the catheter main body 10.

[0034] 2, the guide portion 24 is inserted into the tube 12 from the distal end toward the proximal end of the catheter main body 10 and adhered to the inside of the tube 12, with the abutment end 24C that comes into contact with the sensor 30 located inside the balloon 13. The abutment end 24C of the guide portion 24 comes into contact with the transmission cable 32 of the sensor 30 from the distal side within the second area A2 of the urination lumen 15, thereby guiding the sensor 30. In this way, the guide portion 24 guides the sensor 30 toward the center of the first area A1 of the urination lumen 15.

[0035] The guide portion 24 is made of the same soft material as the tube 12. As a result, the guide portion 24 contracts together with the tube 12 when the balloon 13 expands and the internal pressure of the balloon 13 is applied to the outer periphery of the tube 12. At this time, the contracted tube 12 narrows the gap between the cable holding portion tip 22A of one cable holding portion 22 and the cable holding portion tip 23A of the other cable holding portion 23, so that the transmission cable 32 sandwiched therebetween is firmly held.

[0036] In the catheter main body 10 of this embodiment, the transmission cable 32 of the sensor 30 is held by being sandwiched between a pair of cable holding portions 22, 23 in a first direction D1 (see Figure 4) along the inner circumference of the urination lumen 15, and the guide portion 24 guides the sensor 30 in a second direction D2 (see Figure 4) away from the inner surface of the urination lumen 15.

[0037] The procedure for incorporating the sensor 30 into the tube 12 and the procedure for removing the sensor 30 from the tube 12 will be described below.

[0038] When the sensor 30 is incorporated into the tube 12, first, the sensor 30 is inserted into the second area A2 of the urination lumen 15 through the transmission cable insertion port 20 (see FIG. 3).

[0039] Once the sensor 30 is inserted into the second area A2 of the urination lumen 15, the sensor 30 is then moved through the second area A2 until the sensor body 31 is positioned within the balloon 13. At this time, the second area A2 has a flow path cross section large enough for the sensor body 31 and transmission cable 32 of the sensor 30, so that the sensor 30 can easily pass through the second area A2 of the tube 12.

[0040] The sensor 30 passing through the second area A2 is guided toward the first area A1 as the sensor main body 31 hits the guide portion 24 inside the balloon 13, and the sensor main body 31 passes between the pair of cable holding portions 22, 23 and protrudes from the second area A2 into the first area A1. As a result, the transmission cable 32 is pinched and fixed in the gap between one cable holding portion 22 and the other cable holding portion 23 near the sensor main body 31, and the portion of the transmission cable 32 on the base end side from the pinched portion is held within the second area A2.

[0041] On the other hand, when pulling out the sensor 30 from the tube 12, simply by manually pulling the transmission cable 32 that protrudes from the fixing part 40, the transmission cable 32 and the sensor main body 31 that were sandwiched in the gap between the pair of cable holding parts 22, 23 are pulled into the second area A2 of the urination lumen 15 through the gap between the pair of cable holding parts 22, 23.

[0042] Once the sensor 30 is pulled into the second area A2 of the urination lumen 15, by continuing to pull the transmission cable 32 protruding from the fixed part 40, the sensor 30 moves through the second area A2 to the fixed part 40 and is pulled out from the fixed part 40.

[0043] The balloon catheter 100 according to this embodiment comprises a tube 12 having a urination lumen 15 formed therein that communicates with a tip hole 16 and a side hole 17 formed at the tip, and the tube 12 having a pair of cable holders 22, 23 that sandwich and hold a transmission cable 32 of a sensor 30 in a direction along the inner circumference of the urination lumen 15. This allows the sensor 30 to be sandwiched and held with the sensor main body 31 facing the center of the urination lumen 15, so that the sensor 30 can be properly fixed without the need for adhesive.

[0044] Although the present invention has been described above based on the embodiments, the present invention is not limited to this. For example, in the above embodiment, the transmission cable 32 is held using the cable holders 22 and 23, but the present invention is not limited to this. As long as the sensor 30 can be appropriately fixed, the holders may hold the sensor main body 31 by clamping it.

[0045] In the above embodiment, the sensor 30 is composed of an irradiation unit and an optical fiber, but is not limited to this. Any other type of sensor may be used as long as it is capable of measuring oxygen partial pressure.

[0046] DESCRIPTION OF SYMBOLS 10...Catheter body 11...Tip portion 12...Tube 13...Balloon 13A...Tip-side inflation end 13B...Proximal-side inflation end 14...Branch portion 15...Urination lumen (inner cavity) 16...Tip hole (opening) 17...Side hole (opening) 18...Balloon lumen 19...Balloon injection port 20...Transmission cable insertion port 21...Urination port 22...Cable holding portion 22A...Cable holding portion tip 23...Cable holding portion 23A...Cable holding portion tip 24...Guide portion 24A...Circular surface 24B...Flat surface 24C...Abutment end 30...Sensor 31...Sensor body 32...Transmission cable 40...Fixing portion 41...Fixing portion body 42...Fixing portion cap 43...Tightening portion 43A...Through-hole 100...Balloon catheter A1...First region A2...Second region D1...first direction D2...second direction

Claims

1. A catheter incorporating a sensor having a sensor body attached to one end of a transmission cable, the catheter comprising: a tube having an inner lumen communicating with an opening formed at the tip, the tube having a pair of holding parts for holding the sensor by sandwiching it in a direction along the inner circumference of the lumen.

2. A catheter according to claim 1, further comprising a guide portion for guiding the sensor in a direction away from the inner circumferential surface of the lumen.

3. A catheter according to claim 2, characterized in that the end of the guide portion that comes into contact with the sensor is formed in a wedge shape.

4. A catheter according to claim 2, characterized in that the guide portion is attached to the holding portion.

5. A catheter according to claim 4, characterized in that the guide portion is formed so as to block a cable holding lumen defined by the holding portion along the tube near the tip.

6. A catheter according to claim 2, further comprising a balloon provided on the outer periphery of the tube, and the guide portion has an end that abuts against the sensor and is positioned inside the balloon.

7. A catheter according to claim 1, further comprising a balloon provided on the outer periphery of said tube, said retaining portion being positioned inside said balloon.

8. A catheter according to claim 7, characterized in that the tube contracts as the balloon expands, narrowing the gap between one of the holding portions and the other of the holding portions.

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